This patch makes EC refuse PR swap when the system is powered
through the USB-C port because switching from SNK to SRC will
cause the system to shut down.
BUG=b:65481832
BRANCH=none
TEST=Boot Fizz on USB-C and BJ.
Change-Id: I52c5813adc1ea9b4e69e65599c1794ae43192a1e
Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/655643
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>